Fix install for iOS simulator, and add ability to uninstall (#4223)

packages/flutter_tools/lib/src/device.dart

diff --git a/packages/flutter_tools/lib/src/device.dart b/packages/flutter_tools/lib/src/device.dart
index f67c0d3..d0451f0 100644
--- a/packages/flutter_tools/lib/src/device.dart
+++ b/packages/flutter_tools/lib/src/device.dart
@@ -149,9 +149,15 @@
   /// Whether it is an emulated device running on localhost.
   bool get isLocalEmulator;
 
+  /// Check if a version of the given app is already installed
+  bool isAppInstalled(ApplicationPackage app);
+
   /// Install an app package on the current device
   bool installApp(ApplicationPackage app);
 
+  /// Uninstall an app package from the current device
+  bool uninstallApp(ApplicationPackage app);
+
   /// Check if the device is supported by Flutter
   bool isSupported();
 
@@ -159,9 +165,6 @@
   // supported by Flutter, and, if not, why.
   String supportMessage() => isSupported() ? "Supported" : "Unsupported";
 
-  /// Check if the current version of the given app is already installed
-  bool isAppInstalled(ApplicationPackage app);
-
   TargetPlatform get platform;
 
   /// Get the log reader for this device.